Command Line Interface

class ConventionalChangelog {
  constructor(cwdOrGitClient?: string | ConventionalGitClient);
  loadPreset<T>(preset: PresetParams<T>, loader?: PresetModuleLoader): this;
  config(config: Preset | Promise<Preset>): this;
  readPackage(transform?: PackageTransform): this;
  readPackage(path?: string, transform?: PackageTransform): this;
  package(pkg: Record<string, unknown>): this;
  readRepository(): this;
  repository(infoOrGitUrl: string | Partial<HostedGitInfo>): this;
  options(options: Options): this;
  context(context: Context): this;
  tags(params: GetSemverTagsParams): this;
  commits(params: GetCommitsParams, parserOptions?: ParserStreamOptions): this;
  writer(params: WriterOptions): this;
  write(includeDetails?: false): AsyncGenerator<string, void>;
  write(includeDetails: true): AsyncGenerator<Details<Commit>, void>;
  writeStream(includeDetails?: boolean): NodeJS.ReadableStream;
}

# Install globally
npm install -g conventional-changelog

# Or use locally
npm install conventional-changelog

# Basic usage with Angular preset
conventional-changelog -p angular

# Generate all previous changelogs (first time setup)
conventional-changelog -p angular -r 0

interface Flags {
  /** Read the CHANGELOG from this file (default: CHANGELOG.md) */
  infile?: string;
  /** Write the CHANGELOG to this file (default: infile) */
  outfile?: string;
  /** Output the result to stdout */
  stdout?: boolean;
  /** Name of the preset you want to use */
  preset?: string;
  /** A filepath of where your package.json is located */
  pkg?: string;
  /** Should the newer release be appended to the older release (default: false) */
  append?: boolean;
  /** How many releases to be generated from the latest (default: 1) */
  releaseCount?: number;
  /** If given, unstable tags will be skipped, e.g., x.x.x-alpha.1, x.x.x-rc.2 */
  skipUnstable?: boolean;
  /** Output unreleased changelog */
  outputUnreleased?: boolean;
  /** Verbose output. Use this for debugging (default: false) */
  verbose?: boolean;
  /** A filepath of your config script */
  config?: string;
  /** A filepath of a json that is used to define template variables */
  context?: string;
  /** Generate the CHANGELOG for the first time */
  firstRelease?: boolean;
  /** Generate a changelog for a specific lerna package */
  lernaPackage?: string;
  /** Tag prefix to consider when reading the tags */
  tagPrefix?: string;
}

/**
 * Main CLI program runner
 * @param generator - ConventionalChangelog instance
 * @param flags - Parsed CLI flags
 */
function runProgram(generator: ConventionalChangelog, flags: Flags): Promise<void>;

# Read from and write to CHANGELOG.md (default)
conventional-changelog -p angular

# Custom input and output files
conventional-changelog -p angular -i OLD_CHANGELOG.md -o NEW_CHANGELOG.md

# Output to stdout
conventional-changelog -p angular --stdout

# Use Angular preset (most common)
conventional-changelog -p angular

# Use custom config file
conventional-changelog -n ./changelog.config.js

# Custom package.json location
conventional-changelog -k ./packages/core/package.json

# Use context file for template variables
conventional-changelog -c ./changelog-context.json

# Generate last 3 releases
conventional-changelog -p angular -r 3

# Generate all releases (first time setup)
conventional-changelog -p angular -r 0
# or
conventional-changelog -p angular -f

# Append new releases to bottom of file
conventional-changelog -p angular -a

# Include unreleased changes
conventional-changelog -p angular -u

# Lerna monorepo - specific package
conventional-changelog -p angular -l my-package

# Custom tag prefix
conventional-changelog -p angular -t "release-"

# Scope to specific directory
conventional-changelog -p angular --commit-path packages/core

# Enable verbose logging
conventional-changelog -p angular -v

# Show help
conventional-changelog --help

# 1. Make changes and commit using conventional format
git commit -m "feat: add new feature"
git commit -m "fix: resolve bug in parser"

# 2. Update version in package.json
npm version minor

# 3. Generate changelog
conventional-changelog -p angular -i CHANGELOG.md -o CHANGELOG.md

# 4. Commit changelog and tag
git add CHANGELOG.md
git commit -m "chore: update changelog"
git tag v1.2.0

# 5. Push changes
git push origin main --tags

# Generate complete changelog history
conventional-changelog -p angular -i CHANGELOG.md -o CHANGELOG.md -r 0

# In build script - generate and validate changelog
conventional-changelog -p angular --stdout > /tmp/changelog.md
if [ -s /tmp/changelog.md ]; then
  echo "Changelog generated successfully"
  cat /tmp/changelog.md >> CHANGELOG.md
else
  echo "No new changes to document"
fi

# Generate changelog for specific package in Lerna monorepo
conventional-changelog -p angular -l @my-org/my-package -i packages/my-package/CHANGELOG.md

# Use package-specific config
conventional-changelog -p angular -k packages/my-package/package.json -n packages/my-package/changelog.config.js

module.exports = {
  writer: {
    transform: (commit, context) => {
      // Custom commit transformation
      if (commit.type === 'chore') return null;
      return commit;
    },
    groupBy: 'type',
    commitGroupsSort: 'title',
    commitsSort: ['scope', 'subject']
  },
  parser: {
    noteKeywords: ['BREAKING CHANGE', 'BREAKING CHANGES']
  }
};

{
  "version": "1.2.0",
  "previousTag": "v1.1.0",
  "currentTag": "v1.2.0",
  "packageData": {
    "name": "my-package"
  },
  "host": "https://github.com",
  "owner": "my-org", 
  "repository": "my-repo"
}

# Verbose mode for debugging
conventional-changelog -p angular -v

# Validate git repository
git log --oneline -10  # Check recent commits
git tag -l             # Check available tags

# Test with stdout first
conventional-changelog -p angular --stdout